Pascalle Weijzen, a researcher in the Division of Human Nutrition at Wageningen University in The Netherlands, brought this fact to light by conducting a study in which participants were asked about their intentions in choosing among four snacks-an apple, a banana, a candy bar and a molasses waffle.
The researcher said that about 50 per cent of the participants indicated they would choose the apple or banana-a "healthy" snack.
However, when the researchers presented the participants with the actual snacks a week later, 27 per cent of them switched to the candy bar or waffle.
Over 90 per cent of the unhealthy-choice participants stuck with their intentions and chose the unhealthy snack.
The study included 585 participants who were office employees recruited in their worksite cafeterias.
The researchers said that their observations suggested that intentions are not always tightly linked to people's actual behaviours.
According to them, one explanation for this can be that intentions are usually under cognitive control, while actual choices are often made impulsively, even unconsciously.
Weijzen said: "A substantial gap between healthy snack choice intentions and actual behavior was demonstrated. Despite that gap, the results suggest that individuals who plan to make a healthful choice are more likely to do so than those who plan to make unhealthful choices. Because more than 50 per cent of the population seems to have no intention at all of making a healthful choice, identifying tools by which this group can be motivated to choose a healthful snack is strongly needed."
The study has been published in the Journal of Nutrition Education and Behavior.